In fact, several shell model calculations [1]} had already shown the emergence of deformation around \(^{29}\) F [2]},
providing that the \(2p_{3/2}\)  shell is included [3]}. The universal character of deformation in this region of the nuclear chart is simply a consequence of the Jahn-Teller effect [4]}, [5]}
due to the near-degeneracy of the \(1d_{3/2}\)  and \(2p_{3/2}\)  shells [6]}.
The experimental finding of a negative-parity ground state in \(^{28}\) F thus suggests that some deformations might be present.
